Vegan Sweet Potato Casserole

When a knife slides into the center of a baked sweet potato with no resistance, you know it’s ready to turn into something soft and spoonable. For this vegan sweet potato casserole, I bake the potatoes whole first, then mash the flesh with oat milk, vegan butter, brown sugar, vanilla, and cinnamon.

The topping is a pecan crumble, not a layer of marshmallows, so each serving gets a buttery, nutty contrast against the smooth filling. Cold vegan butter worked into the flour, pecans, and sugar makes the topping clump into coarse crumbs that brown in the oven.

This is a generous casserole for a table of ten, and it can be assembled in a familiar 9×13-inch baking dish. The filling stays tender, the pecans toast on top, and the cinnamon comes through without taking over.

Why Baking the Sweet Potatoes Whole Keeps the Filling From Going Loose

Sweet potatoes can take on extra water when they’re peeled and boiled. Baking them whole keeps the flesh away from a pot of cooking water, so the mash starts out thick and tender rather than damp. That matters here because the filling already gets moisture from oat milk, along with richness from vegan butter.

There’s no need to peel the potatoes before they go into the oven. The skins hold the flesh together while it bakes, and once the potatoes cool enough to handle, the soft centers scoop away easily. Discard the skins and mash the flesh with the other filling ingredients; the result should be mostly smooth, not whipped into a thin puree.

That texture gives the pecan topping a stable base. You want a filling that spreads evenly in the dish and stays soft after baking, with enough body to hold a scoop instead of running across the plate.

The Ingredients That Shape a Creamy Center and Pecan Crumble

• Sweet potatoes — Their natural sweetness and soft flesh make the body of the casserole, so firm, unspoiled potatoes are the best place to spend your attention. Similar-sized potatoes tend to finish baking closer together. There isn’t a simple substitute that gives the same color and soft texture.
• Vegan butter — Use a stick-style butter for a dependable result; tub spreads often contain more water and can make the topping softer. The softened portion blends into the filling, while cold cubes form the crumble. If keeping the dish vegan isn’t important, dairy butter can be used in the same two forms.
• Unsweetened oat milk — It loosens the mash without adding noticeable sweetness. Choose an unflavored carton rather than vanilla oat milk. Unsweetened soy milk works in the same quantity if that’s what you have, though it brings a slightly different taste.
• Vegan light brown sugar — Brown sugar gives the filling a mellow sweetness and helps the pecan topping bake into a crisp, caramel-like crumble. Dark brown sugar can replace it in the same quantity for a deeper molasses note. Check that the sugar you buy is vegan if that matters for your table.
• Pecans and flour — Chopped pecans bring the topping’s toasted crunch, while all-purpose flour gives the butter and sugar crumbs enough structure. Fresh pecans taste brighter, but an everyday bag works well here. Chopped walnuts can stand in for pecans in the same quantity; the topping will taste earthier. A gluten-free 1:1 baking flour is a practical swap for the all-purpose flour, with a slightly different crumb.
• Vanilla and cinnamon — These round out the sweet potato without burying its flavor. Pure vanilla extract is worth using when you have it, but there’s no need to buy an expensive brand for a baked casserole. Keep the cinnamon fresh enough to smell warm and fragrant when you open the jar.

From Baked Potatoes to a Golden Pecan Top

Bake the Potatoes Until Their Centers Give Easily

Heat the oven to 400°F and arrange the scrubbed sweet potatoes on a rimmed baking sheet. Bake them for 50 to 65 minutes, checking for tenderness by sliding a knife into the centers. If the knife meets a firm spot, give the potatoes more time rather than trying to mash them underdone. Let them cool until they’re easy to handle before halving and scooping out the flesh.

Mash a Thick, Mostly Smooth Filling

Lower the oven to 350°F once the potatoes are out. Add the sweet potato flesh to a large bowl with the softened vegan butter, oat milk, filling portion of brown sugar, vanilla, cinnamon, and kosher salt. Mash until mostly smooth; a few soft sweet potato flecks are fine, but the mixture should spread without stiff lumps. If it looks loose, don’t pour in extra oat milk.

Work the Cold Butter Into the Pecan Crumbs

Stir the chopped pecans, flour, and topping portion of brown sugar together first. Add the cold, cubed vegan butter and work it in with your fingers until coarse crumbs form. Stop once the mixture has a mix of small and larger clumps; rubbing it until uniformly fine won’t give you the same crisp, craggy top. Keep the butter cold as you work so it stays in distinct crumbs.

Top the Filling and Bake Until Golden

Grease a 9×13-inch baking dish with vegan butter, then spread the sweet potato filling evenly in it. Scatter the pecan mixture over the surface so the crumbs are distributed from edge to edge. Bake at 350°F for 25 to 30 minutes, until the topping is golden and the casserole is hot throughout. Watch the color toward the end so the pecans don’t get too dark.

Easy Swaps That Keep the Casserole’s Texture in Balance

Questions That Come Up Before This Casserole Goes in the Oven

Vegan Sweet Potato Casserole

Vegan sweet potato casserole pairs creamy, cinnamon-spiced sweet potatoes with a crisp pecan and brown sugar topping. It bakes in a 9x13-inch dish until golden and hot throughout.

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 1 hour hr 25 minutes mins

Resting 10 minutes mins

Total Time 1 hour hr 55 minutes mins

Servings: 10 servings

Course: Side Dish

Cuisine: American

Calories: 405

Ingredients Equipment Method Notes

Ingredients

  

Make the sweet potato filling

• 4 lb sweet potatoes scrubbed
• 9 tbsp vegan butter divided (1 tablespoon for the baking dish, 4 tablespoons softened for the filling, and 4 tablespoons cold and cubed for the topping)
• 0.5 cup unsweetened oat milk
• 0.75 cup light brown sugar vegan, divided (1/4 cup for the filling and 1/2 cup for the topping)
• 1 tsp vanilla extract
• 1 tsp ground cinnamon
• 0.5 tsp kosher salt

Make the pecan topping

• 1 cup chopped pecans
• 0.5 cup all-purpose flour

Equipment

• 1 rimmed baking sheet
• 1 9x13-inch baking dish

Method

 

Make the sweet potato filling

1. Heat the oven to 400°F and bake the sweet potatoes on a rimmed baking sheet for 50 to 65 minutes, until a knife slides easily into the centers.
2. Let the potatoes cool until easy to handle, then halve them and scoop the flesh into a large bowl; discard the skins.
3. Reduce the oven to 350°F and mash the sweet potatoes with 4 tablespoons softened vegan butter, the oat milk, 1/4 cup brown sugar, vanilla, cinnamon, and salt until mostly smooth.

Make the pecan topping

1. Mix the pecans, flour, and 1/2 cup brown sugar, then work in 4 tablespoons cold vegan butter with your fingers until coarse crumbs form.

Assemble and bake

1. Grease a 9x13-inch baking dish with the remaining 1 tablespoon vegan butter, spread the sweet potato mixture evenly in the dish, and scatter the pecan topping over it.
2. Bake at 350°F for 25 to 30 minutes, until the topping is golden and the casserole is hot throughout.
3. Let the casserole rest for 10 minutes before serving.

Notes

For the smoothest filling, bake the sweet potatoes until a knife slides easily into their centers. Store covered in the refrigerator for up to 4 days; freeze for up to 2 months. For a gluten-free version, use a 1:1 gluten-free flour blend in place of the all-purpose flour.